55575621 has 6 divisors (see below), whose sum is σ = 80275910. Its totient is φ = 37050408.

The previous prime is 55575617. The next prime is 55575643. The reversal of 55575621 is 12657555.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 34644996 + 20930625 = 5886^2 + 4575^2 .

It is not a de Polignac number, because 55575621 - 2² = 55575617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55575661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3087526 + ... + 3087543.

Almost surely, 2^55575621 is an apocalyptic number.

It is an amenable number.

55575621 is a deficient number, since it is larger than the sum of its proper divisors (24700289).

55575621 is a wasteful number, since it uses less digits than its factorization.

55575621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6175075 (or 6175072 counting only the distinct ones).

The product of its digits is 52500, while the sum is 36.

The square root of 55575621 is about 7454.9058344153. The cubic root of 55575621 is about 381.6173470550.

It can be divided in two parts, 555 and 75621, that added together give a square (76176 = 276²).

The spelling of 55575621 in words is "fifty-five million, five hundred seventy-five thousand, six hundred twenty-one".